Adjacent GATA and kappa B-like motifs regulate the expression of a Drosophila immune gene

The GATA motif is a well known positive cis-regulatory element in vertebrates, In this work we report experimental evidence for the direct participation of a GATA motif in the expression of the Drosophila antibacterial peptide gene Cecropin A1. Previously we have shown that a kappa B-like site is necessary for Cecropin Al gene expression, Here we present evidence that the Drosophila Rel protein which binds to the kappa B-like site requires an intact GATA site for maximal Dif-mediated transactivation of the Cecropin Al gene. We show that a Drosophila blood cell line contains factors binding specifically to the GATA motif of the Cecropin Al gene, The GATA binding activity is likely to include member(s) of the GATA family of transcriptional regulators. We show that the promoters of several inducible insect immune genes possess GATA sites 0-12 base pairs away from kappa B-like sites in functionally important promoter regions. Clusters of GATA and kappa B sites are also observed in the promoters of two important mammalian immune genes, namely IL6 and IL3. The consistent proximity of GATA and kappa B sites appears to be a common theme in the immune gene expression of insects and mammals.